js global css variable code example
Example 1: how to change css variable in javascript
document.documentElement.style.setProperty("--main-background-color", "green");
Example 2: set css variable from javascript
document.documentElement.style.cssText = "--tab-count: 3";
/or/
document.documentElement.style.setProperty("--tab-count", 5);
/or/
document.documentElement.setAttribute("style", "--tab-count: 5");